shiavm006 opened a new issue, #623: URL: https://github.com/apache/mahout/issues/623
### Description The U-gate implementation in Cirq and Amazon Braket backends uses incorrect decomposition, producing wrong quantum states and breaking cross-backend consistency. The universal single-qubit U-gate should decompose as U(θ, φ, λ) = Rz(φ) · Ry(θ) · Rz(λ), but both backends currently use incorrect gate sequences. ### Steps to Reproduce 1. Create a quantum circuit with 1 qubit using Cirq or Amazon Braket backend 2. Apply U-gate with parameters: `apply_u_gate(0, theta=π/2, phi=π/4, lambd=π/8)` 3. Execute circuit and measure state vector 4. Compare results with Qiskit backend using same parameters 5. Observe different quantum states across backends ### Expected Behavior All three backends (Qiskit, Cirq, Amazon Braket) should produce identical quantum states for the same U-gate parameters. The correct decomposition is: U(θ, φ, λ) = Rz(φ) · Ry(θ) · Rz(λ) ### Actual Behavior Qiskit (CORRECT):Uses native `circuit.u(theta, phi, lambd, qubit_index)` - produces correct states -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected]
